With the increased use of wireless devices, knowledge of one device's proximity to another has many applications. For example, a system may allow for wireless devices within its proximity to control aspects of the system. That system therefore needs a way to identify a device requesting control and ensure that device is close enough to the system to warrant granting control to the device.
Some common forms of communications between devices having close proximity are near field communications (NFC), Bluetooth, and infrared. In the example above, the system and the device would exchange information using one of these communication forms. The information exchanged would allow the system and the device to be aware of their proximity to each other, and set up a communication channel over communication networks, such as Ethernet, WIFI, or the Internet.
The common forms of close proximity communications each have their own drawbacks. For example, NFC requires proximity to be within a couple inches, Bluetooth requires a pairing procedure, and infrared required line of sight. Acoustic close proximity communications have been envisioned to overcome some of the above drawbacks. However, current acoustic methods are still subject to background acoustic noise interference and generate sounds that may be unpleasant to any person within earshot of the transmission.
Overview
Embodiments disclosed herein provide systems and methods for acoustically transferring information between systems. In a particular embodiment, a method provides identifying information for acoustic transfer and determining an amount of time corresponding to the information. The method further provides acoustically transmitting a signal at a first time and, upon the amount of time elapsing since the first time, acoustically transmitting the signal at a second time.
In some embodiments, the method provides receiving the signal transmitted at the first time and the signal transmitted at the second time and deriving the information based on a time period between receipt of the signal transmitted at the first time and receipt of the signal transmitted at the second time.
In some embodiments, the method provides that deriving the information based on a time period between receipt of the signal transmitted at the first time and receipt of the signal transmitted at the second time comprises determining a correlation between the signal transmitted at the first time and the signal transmitted at the second time, determining the time period as a time between peaks resulting from the correlation, and identifying the information that corresponds to the time period.
In some embodiments, the method provides that the amount of time comprises an amount of digital audio samples.
In some embodiments, the method provides that the information comprises a number and the number equals the amount of digital audio samples.
In some embodiments, the method provides, before the first time, acoustically transmitting two synchronization signals for receiver synchronization, wherein a time period separating the transmission of the two synchronization signals is known to a receiver system.
In some embodiments, the two synchronization signals comprise two instances of the signal.
In some embodiments, the method provides identifying second information for acoustic transfer, determining a second amount of time corresponding to the second information, and, upon the second amount of time elapsing since the second time, acoustically transmitting the signal at a third time.
In some embodiments, the method provides that the signal comprises frequencies audible to the human ear.
In another embodiment, a receiver system for acoustically receiving information is provided. The system includes an acoustic receiver configured to receive a signal at a first time and, after the first time, receive the signal at a second time. The system also includes a processing system configured to derive information based on a time period between the first time and the second time.
In some embodiments, the processing system configured to derive information based on a time period between the first time and the second time comprises the processing system configured to determine a correlation between the signal transmitted at the first time and the signal transmitted at the second time, determine the time period as a time between peaks resulting from the correlation, and identify the information that corresponds to the time period.
In some embodiments, the acoustic receiver is configured to, before the first time, receive two synchronization signals for receiver synchronization, wherein a time period separating the transmission of the two synchronization signals is known to the receiver system.
In some embodiments, the acoustic receiver is configured to receive the signal at a third time after the second time and the processing system is configured to derive second information based on a second time period between the second time and the third time.
In yet another embodiment, a transmitter system for acoustically transferring information is provided. The transmitter system includes a processing system configured to identify information for acoustic transfer and determine an amount of time corresponding to the information. The transmitter system further includes an acoustic transmitter configured to acoustically transmit a signal at a first time and, upon the amount of time elapsing since the first time, acoustically transmit the signal at a second time.
In some embodiments, the acoustic transmitter is configured to acoustically transmit, before the first time, two synchronization signals for receiver synchronization, wherein a time period separating the transmission of the two synchronization signals is known to a receiver system.
In some embodiments, the processing system configured to identify second information for acoustic transfer and determine a second amount of time corresponding to the second information and the acoustic transmitter is configured to, upon the second amount of time elapsing since the second time, acoustically transmit the signal at a third time.